Piotr Nikolaievitch Rasputin was born on the Soviet collective farm called the Ust-Ordynski Collective. As Colossus, he can convert his body tissues into organic steel at will (process is virtually instantaneous). However, Rasputin cannot become partially or selectively armored; his body is either entirely covered or not. As a teen, he was sufficiently strong enough to lift seventy tons. As a fully-mature adult, his strength increased to the point where he’s able to lift over a hundred [easily]. Even without transforming into his metal form, he could lift twice his body weight (700 lbs). Just like all metal, his skin was vulnerable to the anti-metal vibranium. He can also be damaged when attacked by something made from a stronger material (like Wolverine’s adamantium claws). As Juggernaut, Colossus was able to be harmed by exceedingly high levels of mental&mystical attacks despite invulnerability to physical damage.
Heavy Metal, by kanthesis.